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Biomedical subjects

H Bekki

Publications and source records attributed to H Bekki.

11 recordsLinked to original sources
PubMed1986

Relationship of exercise or pacing induced ST segment depression and myocardial lactate metabolism in patients with hypertrophic cardiomyopathy.

To elucidate a mechanism and clinical implications of chest pain and ST segment depression during exercise in patients with hypertrophic cardiomyopathy (HCM), we investigated myocardial lactate metabolism during atrial pacing in 18 patients with HCM and 7 control subjects with normal coronary arteriograms. At an average peak pacing rate of 146 beats/min, 11 patients with HCM showed the lactate extraction ratio decreasing to less than 5%, and 6 of them produced lactate, suggesting the development of myocardial ischemia. These 11 patients with abnormal lactate metabolism demonstrated ST segment depression (82%) and chest pain (73%) during pacing and also presented abnormal results (55%) on an exercise stress test. These abnormal findings were not observed in the other 7 patients who had ratios of 5% or more at peak pacing. These observations suggest that ST segment depression and chest pain are manifestations of myocardial ischemia even in patients with HCM who have normal coronary arteriograms, and that patients with pacing induced abnormal lactate metabolism are at an increased risk of developing myocardial ischemia during exercise.

Adolescent↗
PubMed1983

Aneurysm of the left aortic sinus causing acute myocardial infarction.

A 30-year-old female had an acute myocardial infarction complicated by congestive heart failure. Angiography demonstrated an aneurysm in the area of the left aortic sinus. The aneurysm compressed and displaced the main trunk of the left coronary artery and the proximal portion of the left anterior descending artery. This aneurysm was considered to be the cause of the infarction. Aortic valve replacement and removal of the aneurysm were performed. Postoperative studies revealed good function of the replaced valve, good antegrade filling of the left coronary artery, and improved left ventricular function.

Adult↗
PubMed1983

Hemodynamic evaluation of exercise-induced ST-segment depression and elevation in ischemic heart disease. Left ventricular cineangiography during exercise.

In order to elucidate the hemodynamic significance of exercise-induced ST-segment shifts in ischemic heart disease, left ventricular cineangiography was carried out in 41 patients at rest and during supine bicycle ergometer exercise. These patients were divided into 2 groups, that is, a normal coronary artery group (6 patients), having neither significant coronary artery stenosis nor exercise-induced ST-segment shifts, and a diseased group (35 patients) having significant coronary artery stenosis (inner-diameter stenosis greater than or equal to 75%). The latter was further divided into 3 subgroups according to exercise-induced ST-segment shifts: ST-unchanged group (17 patients), ST-depression group (11 patients) and ST-elevation group (7 patients). In the normal coronary artery and ST-unchanged groups, exercise produced an increase in left ventricular end-diastolic volume index (LVEDVI), a decrease in left ventricular end-systolic volume index (LVESVI) and increases in stroke index and ejection fraction. In the ST-depression group, the appearance or aggravation of left ventricular wall motion abnormality was induced at the site of coronary artery stenosis by exercise in 9 patients. Both LVEDVI and LVESVI increased, stroke index remained unchanged, and ejection fraction decreased during exercise. In the ST-elevation group, ST-segment elevation was induced in leads with abnormal Q waves. In 2 patients, exercise induced aggravation of wall motion abnormality at the infarctional segment. LVESVI increased, but LVEDVI showed little increase, and stroke index and ejection fraction tended to decrease during exercise. In the ST-depression group, exercise-induced left ventricular pump dysfunction was due to lowered contractility (increased LVESVI) caused by transient myocardial ischemia. In the ST-elevation group, exercise-induced pump dysfunction was mainly due to lowered contractility, and in some of them, the findings suggested that transient myocardial ischemia at or around the region of infarction might be the cause of pump dysfunction. In addition, a poor compensatory effect of the Frank-Starling mechanism seemed to play a role in the onset of such dysfunction in this group.

Adult↗
PubMed1982

[Exercise two-dimensional echocardiography: correlation between exercise induced asynergy and coronary artery lesions].

Exercise two-dimensional (2-D) echocardiography was performed in patients with suspected coronary artery disease, and exercise induced left ventricular asynergy was evaluated qualitatively and was compared with the coronary artery stenosis and electrocardiographic ST changes. Subjects were 12 patients with angina of effort, 8 patients with spontaneous angina, 8 patients with chest pain syndrome with the normal coronary artery, and 7 patients with hypertrophic cardiomyopathy (HCM). Cases with myocardial infarction were excluded from this study. 1) Left ventricular asynergy during exercise was observed in 10 and ST depression in 11 of 12 patients with angina of effort. In patients with spontaneous angina, left ventricular asynergy and ST depression during exercise were observed in 2 of 8 patients without anginal pain, and both patients had coronary artery stenosis of 90% or more. 2) Exercise induced asynergy was also observed in 4 of 7 patients with HCM without coronary artery stenosis. It seemed likely that the markedly hypertrophied myocardium and impairment of left ventricular compliance and relaxation may induce relative myocardial ischemia.

Adult↗
PubMed1982

[Cross-sectional echocardiographic visualization of the infarcted site in myocardial infarction: correlation with electrocardiographic and coronary angiographic findings].

Three dimensional assessment of the site of myocardial infarct was performed using cross-sectional echocardiography in 68 patients with old myocardial infarction. Patients with a history or electrocardiographic findings suggestive of double or multiple infarctions were excluded from the study. In patients with abnormal Q waves in V1 to V3, a regional wall motion abnormality (asynergy) was observed in the anterior portion of the interventricular septum (IVS) and the anterior free wall of the left ventricle (LV) which was extended from the base to apex. Most of them had a significant stenosis in the left anterior descending artery (LAD) distal to the first diagonal branch. Patients with Q waves in V1 to V5 or V6 showed extensive asynergy in the anterior IVS, anterior and lateral free walls of the LV extended from the base to apex. LAD stenosis proximal to the first diagonal branch seemed to be the corresponding coronary lesion. In patients with Q waves in V3 to V5 or V6, asynergy was limited to the apical half of the anterior wall of the LV. In patients with Q waves in II, III and a VF, asynergy was observed in the basal half of the posterior wall and the posterior portion of the IVS.

Coronary Angiography↗
PubMed1981

[Detection of exercise induced left ventricular asynergy by two-dimensional echocardiography (author's transl)].

In order to detect an exercise induced asynergy, cross-sectional echocardiography was performed during multistage maximal bicycle ergometer stress test in the supine position. 1) Left ventricular (LV) asynergy occurred earlier than or simultaneously with the appreciable ST segment change. 2) In patients with angina, LV asynergy appeared in the area of dominant coronary stenosis, while ST depression was seen in V3-6 as well as II, III and aVF, despite of the localized area of asynergy. 3) In patients with myocardial infarction, LV asynergy increased or extended over or around the infarcted area except one case, ST segment elevated in the leads over the infarction with abnormal Q waves and depressed in the reciprocal leads. These observations revealed that ST depression does not necessarily mean an occurrence of new ischemia over the corresponding area in myocardial infarction. Thus exercise cross-sectional echocardiography was demonstrated to be a good method to detect an exercise induced ischemia and would be particularly valuable in view of the coronary artery bypass.

Adult↗